Supporting device for a chair

ABSTRACT

A supporting device for a chair in accordance with the present invention comprises a board comprising two opposite lateral wings extending from a side of the board and defining a compartment therebetween, each of the opposite lateral wings having a top edge. Plural resilient members extend between the top edges of the opposite lateral wings. An elastic lining pad is mounted to an outer side of the plural resilient members. When an external force is exerted on the supporting device, the plural resilient members absorbs the external force by means of deforming into the compartment, and the resilient members return to their original shapes when the external force is removed.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a supporting device for a chair. In particular, the present invention relates to a supporting device such as a seat or backrest for a chair such as an office chair.

[0003] 2. Description of the Related Art

[0004]FIG. 10 of the drawings illustrates a conventional backrest for a chair. The backrest comprises a board 1, a piece of sponge 2, and an outer cover 3 for covering the board 1 and the piece of sponge 2 for aesthetic purpose. The piece of sponge 2 is deformed when an external force is exerted on the backrest (e.g., the user's back is lying on the backrest), and it returns to its original shape after the external force is removed. However, the returning effect of the piece of sponge 2 is poor if it is has a low density. But the air permeability of the piece of the sponge 2 is poor if it has a high density for obtaining a satisfactory returning effect. The user will feel hot and uncomfortable at the back. In addition, the returning effect provided by the piece of sponge deteriorates after a period of time and thus should be replaced from time to time. The discarded sponge causes an environmental problem.

SUMMARY OF THE INVENTION

[0005] An object of the present invention is to provide a supporting device such as a seat or backrest for a chair such as an office chair.

[0006] A supporting device for a chair in accordance with the present invention comprises a board comprising two opposite lateral wings extending from a side of the board and defining a compartment therebetween, each opposite lateral wing having a top edge. Plural resilient members extend between the top edges of the opposite lateral wings. An elastic lining pad is mounted to an outer side of the plural resilient members. When an external force is exerted on the supporting device, the plural resilient members absorbs the external force by means of deforming into the compartment, and the resilient members return to their original shapes when the external force is removed.

[0007] Plural ribs extend between the opposite lateral walls of the board for reinforcing the board. Air is allowed to circulate in the compartment to provide a good permeability. An elastic support is mounted between the plural resilient members and the elastic lining pad for preventing the elastic lining pad from entering into the compartment. An outer cover is provided for housing the board and the elastic lining pad. Each resilient member is a rubber strip or a spring.

[0008] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a perspective view of a perspective view of a backrest in accordance with the present invention.

[0010]FIG. 2 is an exploded perspective view of the backrest in accordance with the present invention.

[0011]FIG. 3 is a perspective view of a seat in accordance with the present invention.

[0012]FIG. 4 is an exploded perspective view of the seat in accordance with the present invention.

[0013]FIG. 5 is an exploded perspective view of an upper portion of a chair in accordance with the present invention.

[0014]FIG. 6 is a perspective view of the chair in accordance with the present invention.

[0015]FIG. 7 is a sectional view taken along plane A-A in FIG. 6.

[0016]FIG. 8 is an exploded perspective view of a modified embodiment of the backrest in accordance with the present invention.

[0017]FIG. 9 is an exploded perspective view of a further modified embodiment of the backrest in accordance with the present invention.

[0018]FIG. 10 is an exploded perspective view of a conventional chair backrest.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Referring to FIGS. 1 through 9 and initially to FIGS. 1 and 2, a backrest 10 in accordance with the present invention generally comprises a board 11, an elastic support 12, an elastic lining pad 13, and an outer cover 14. The board 11 can be made of any suitable material. In this embodiment, the board 11 is formed by means of molding injection. The board 11 comprises two opposite lateral wings 111 extending from a front side of the board 11 and defining a compartment 112 therebetween. Plural ribs 113 extend between the opposite lateral wings 111 for reinforcing the structure of the board 11. Plural resilient members 114 extend between top edges 116 of the opposite lateral wings 111, which will be described later. In this embodiment, each resilient member 114 is a rubber strip. The elastic support 12 is mounted to the outer sides of the resilient members 114 and thus encloses the compartment 112. The elastic lining pad 13 is mounted to an outer side of the elastic support 12 and preferably made of sponge. The outer cover 14 houses the board 11, the elastic support 12, and the elastic lining pad 13 and is made of a suitable material such as leather. The board 11 may further comprises two pegs 115 on an outer face of one of the opposite lateral walls 111. The pegs 115 are exposed outside the outer cover 14 and each have a screw hole (not labeled).

[0020] Referring to FIGS. 3 and 4, a seat 20 in accordance with the present invention generally comprises a board 21, an elastic support 22, an elastic lining pad 23, and an outer cover 24. The board 21 can be made of any suitable material. In this embodiment, the board 21 is formed by means of molding injection. The board 21 comprises two opposite lateral wings 211 extending from a front side of the board 21 and defining a compartment 212 therebetween. Plural ribs 213 extend between the opposite lateral wings 211 for reinforcing the structure of the board 21. Plural resilient members 214 extend between top edges 216 of the opposite lateral wings 211, which will be described later. In this embodiment, each resilient member 214 is a rubber strip. The elastic support 22 is mounted to the outer sides of the resilient members 214 and thus encloses the compartment 212. The elastic lining pad 23 is mounted to an outer side of the elastic support 22 and preferably made of sponge. The outer cover 24 houses the board 21, the elastic support 22, and the elastic lining pad 23 and is made of a suitable material such as leather. The board 21 may further comprises two pegs 215 on an outer face of one of the opposite lateral walls 211. The pegs 215 are exposed outside the outer cover 24 and each have a screw hole (not labeled).

[0021] In general, the backrest 10 and the seat 20 are almost identical in structure except for the outlines. FIGS. 5 and 6 illustrate a chair, particularly an office chair, comprising the backrest 10, the seat 20, and two armrests 30. Each armrest 30 has two holes 32 in a lower side thereof and two holes 31 in a rear end thereof, and bolts or screws 40 are extended through the holes 31, 32 and the screw holes 115 and 215 of the backrest 10 and the seat 20 to thereby assemble the armrests 30 to the backrest 10 and the seat 20. Referring to FIG. 7, when an external force is exerted on the supporting device (i.e., the backrest 10 or the seat 20), it is absorbed by the resilient members 14, 24. The elastic support 12, 22 prevents entrance of the elastic lining pad 13, 23 into the compartment 11, 21. The elastic lining pad 13, 23 provides the user with a soft, comfort support. The resilient members 14, 24 are less likely to deform permanently when compared with those in the conventional design. The compartment 112, 212 allows air to circulate therein and thus prevents overheat and prolongs the life of the supporting device.

[0022]FIGS. 8 and 9 are exploded perspective views of modified embodiments of the supporting device (in the form of a backrest) in accordance with the present invention. In the embodiments shown in FIGS. 8 and 9, the resilient members 114 are coil springs and wavy springs, respectively. In addition, the elastic support 12 in the first embodiment is omitted in the embodiment shown in FIG. 9.

[0023] In conclusion, when an external force is exerted on the supporting device, the plural resilient members 114, 214 absorbs the external force by means of deforming into the compartment 112, 212, and the resilient members 114; 214 return to their original shapes when the external force is removed. By means of provision of the supporting device in accordance with the present invention, the life of the backrest or seat is prolonged while providing an improved support.

[0024] Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed. 

What is claimed is:
 1. A supporting device for a chair, comprising: a board comprising two opposite lateral wings extending from a side of the board and defining a compartment therebetween, each of the opposite lateral wings having a top edge; plural resilient members extending between the top edges of the opposite lateral wings; and an elastic lining pad mounted to an outer side of the plural resilient members; wherein when an external force is exerted on the supporting device, the plural resilient members absorbs the external force by means of deforming into the compartment, and the resilient members return to their original shapes when the external force is removed.
 2. The supporting device for a chair as claimed in claim 1, further comprising plural ribs extending between the opposite lateral walls of the board for reinforcing the board.
 3. The supporting device for a chair as claimed in claim 1, wherein air is allowed to circulate in the compartment to provide a good permeability.
 4. The supporting device for a chair as claimed in claim 1, further comprising an elastic support between the plural resilient members and the elastic lining pad for preventing the elastic lining pad from entering into the compartment.
 5. The supporting device for a chair as claimed in claim 1, further comprising an outer cover for housing the board and the elastic lining pad.
 6. The supporting device for a chair as claimed in claim 1, wherein the board is formed by molding injection.
 7. The supporting device for a chair as claimed in claim 1, wherein each said resilient member is a rubber strip.
 8. The supporting device for a chair as claimed in claim 1, wherein each said resilient member is a spring. 